Ozawa Yuichi, Abe Takefumi, Omae Minako, Matsui Takashi, Kato Masato, Hasegawa Hirotsugu, Enomoto Yasunori, Ishihara Takeaki, Inui Naoki, Yamada Kazunari, Yokomura Koshi, Suda Takafumi
Department of Respiratory Medicine, Respiratory Disease Center, Seirei Mikatahara General Hospital, Hamamatsu, Japan.
Department of Radiation Oncology, Seirei Mikatahara General Hospital, Hamamatsu, Japan.
PLoS One. 2015 Oct 13;10(10):e0140437. doi: 10.1371/journal.pone.0140437. eCollection 2015.
This study investigated the clinical characteristics and predictive factors for developing acute extended radiation pneumonitis with a focus on the presence and radiological characteristics of preexisting interstitial lung disease.
Of 1429 irradiations for lung cancer from May 2006 to August 2013, we reviewed 651 irradiations involving the lung field. The presence, compatibility with usual interstitial pneumonia, and occupying area of preexisting interstitial lung disease were retrospectively evaluated by pretreatment computed tomography. Cases of non-infectious, non-cardiogenic, acute respiratory failure with an extended bilateral shadow developing within 30 days after the last irradiation were defined as acute extended radiation pneumonitis.
Nine (1.4%) patients developed acute extended radiation pneumonitis a mean of 6.7 days after the last irradiation. Although preexisting interstitial lung disease was found in 13% of patients (84 patients), 78% of patients (7 patients) with acute extended radiation pneumonitis cases had preexisting interstitial lung disease, which resulted in incidences of acute extended radiation pneumonitis of 0.35 and 8.3% in patients without and with preexisting interstitial lung disease, respectively. Multivariate logistic analysis indicated that the presence of preexisting interstitial lung disease (odds ratio = 22.6; 95% confidence interval = 5.29-155; p < 0.001) and performance status (≥2; odds ratio = 4.22; 95% confidence interval = 1.06-20.8; p = 0.049) were significant predictive factors. Further analysis of the 84 patients with preexisting interstitial lung disease revealed that involvement of more than 10% of the lung field was the only independent predictive factor associated with the risk of acute extended radiation pneumonitis (odds ratio = 6.14; 95% confidence interval = 1.0-37.4); p = 0.038).
Pretreatment computed tomography evaluations of the presence of and area size occupied by preexisting interstitial lung disease should be assessed for safer irradiation of areas involving the lung field.
本研究调查了急性放射性肺炎的临床特征及预测因素，重点关注既往间质性肺病的存在情况及影像学特征。
在2006年5月至2013年8月间的1429例肺癌放疗病例中，我们回顾了651例涉及肺野的放疗病例。通过治疗前计算机断层扫描回顾性评估既往间质性肺病的存在情况、与寻常型间质性肺炎的相符性以及累及面积。将最后一次放疗后30天内出现双侧广泛阴影的非感染性、非心源性急性呼吸衰竭病例定义为急性放射性肺炎。
9例（1.4%）患者在最后一次放疗后平均6.7天发生急性放射性肺炎。虽然13%（84例）的患者存在既往间质性肺病，但78%（7例）的急性放射性肺炎患者存在既往间质性肺病，无既往间质性肺病和有既往间质性肺病患者的急性放射性肺炎发生率分别为0.35%和8.3%。多因素逻辑分析表明，既往间质性肺病的存在（比值比=22.6；95%置信区间=5.29 - 155；p<0.001）和体能状态（≥2；比值比=4.22；95%置信区间=1.06 - 20.8；p = 0.049）是显著的预测因素。对84例有既往间质性肺病的患者进行进一步分析发现，肺野累及超过10%是与急性放射性肺炎风险相关的唯一独立预测因素（比值比=6.14；95%置信区间=1.0 - 37.4；p = 0.038）。
为更安全地对涉及肺野的区域进行放疗，应通过治疗前计算机断层扫描评估既往间质性肺病的存在情况及累及面积大小。
